PT140 · S2 · Q19 Viewers surveyed immediately after

The author wasn't selling us a story where "Lopez's debate performance was integral to her victory", and this answer would only be weakening that sort of claim. To the contrary, the author is saying "Lopez's debate performance probably meant very little, for her voters had already decided on her and because of that bias they rationalized that she had made the better arguments in the debate". Our author is assuming that most of the debate watchers were already Lopez voters, not that most of Lopez's voters were debate watchers.

If we were allowed to assume that the people who were in the live audience were undecided voters, and THEY thought that Tanner made the better arguments, that would strengthen the author's argument that people who said Lopez made better arguments were already biased in favor of her. Since we don't know anything about which type of people were in the live audience, it's really just unclear if this has any impact, but it's more likely to Strengthen than Weaken.

Since the author thinks that people saying Lopez won were biased, she is picturing people who already knew they were gonna vote for Lopez and then "saw what they wanted to see" in the debate. So saying, "Hey, author, most of the debate viewers were Tanner voters" seems to undercut that assumption. But ultimately if we compare the impact of this to that of (D), both answers are trying to convey that "the people watching the debate were NOT pro-Lopez", but this answer is talking about all people who watched the debate. Meanwhile (D) is specifically addressing the people in the survey, and the conclusion is specifically about survey respondents, so (D) more effectively attacks the idea that these survey respondents were pro-Lopez going into the debate.

This somewhat undermines the plausibility of the author's story that the debate viewers surveyed were biased in favor of Lopez. After all, in a 50/50 election, if the debate viewers surveyed were a representative sample of the electorate, then the debate viewers would be about evenly divided in terms of who was biased in favor of Lopez vs. in favor of Tanner. However, the survey results aren't a math mismatch for the results of the election. If the survey had been 4 to 1 in favor of Lopez winning the debate, whereas the election results were more like 49% vs. 48% in favor of Lopez, then it would be pretty implausible to say the 4 to 1 survey responses were because of a hugely slanted bias towards Lopez in the electorate. But all we know is that survey respondents tended to think Lopez made the better arguments, which just means "over 50% favored Lopez". A post-debate survey that narrowly tilts toward Lopez could be the result of a narrowly tilting bias in favor of Lopez, that results in a narrowly won election. Ultimately, we get to reject this answer by comparing its fuzzy impact to the clear, direct impact of the correct answer.